The invention relates to a discharge nozzle for centrifugal separators in which concentrate is continuously discharged from the peripheral portion of the separating chamber, the discharge nozzle being installed in the outer periphery of the drum on a smaller diameter on the drum than the outer peripheral portion of the separating chamber. The discharge nozzle is mounted rotatably in the drum periphery and sealed by a sealing ring and has an inlet orifice and a discharge orifice plus a locking projection which engages a corresponding recess in the drum periphery so as to hold the discharge nozzle in place.
A discharge nozzle of this kind is known, for example, from U.S. Pat. No. 2,695,748, according to which nozzles are disposed at equal intervals on the circumference of the centrifugal separator and can be disposed either at the periphery of the drum or on a smaller diameter on the drum than the peripheral portion of the separating chamber. To facilitate the replacement of worn nozzles or the cleaning of the discharge orifices in the nozzle, it is common practice to fasten the nozzles externally and removably in the drum wall, corresponding installation openings being provided for this purpose in the separator casing at the level of the nozzles in the drum wall. The nozzles have to be aimed when they are installed so that the jet will emerge from the nozzles tangentially to the drum diameter and against the direction of rotation of the drum.
If the nozzle jet deviates from the tangential direction, in the case of outwardly aimed nozzles a greater amount of power is required and hence the motor may become overloaded, and in the case of inwardly aimed nozzles the drum may be damaged and thus safety of operation may be impaired.
In the known centrifugal separators, the aim of the nozzles is determined by the operator when they are installed. Since the nozzles are often disposed on the bottom of the drum, where the operator has difficulty in seeing them, the aim of the nozzles is often faulty, with the disadvantages described above.
Tangentially disposed nozzles are known, as represented, for example, in German Pat. No. 829,880, where they are precisely aligned in the drum wall, but they have the disadvantage of making the drum more costly to produce, and the nozzles themselves are harder to clean and hence the danger of clogging is increased.
For these reasons, in present-day construction, nozzle drums are provided almost exclusively with nozzles which are inserted axially.